Cancer of the colon-rectum and stomach

personal notes from dr. Claudio Italiano, gastroenterologist
Etiology of rectal cancer.

It 's the most common cancer in developed countries and is responsible for about 10% of deaths from malignant. It occurs at all ages but is most affected in the sixth and seventh decades. It affects both sexes with almost the same frequency, but is more common in males. In 2000, 37,733 new cases in Italy in 20,457 males and 17,276 females. It 'was responsible for 16,646 deaths, with 73% of cases the cancer occurred in 27% colon and rectum. With regard to age in 3% of cases were patients with <49 aa; 9% aa 50-29, 60-69 AA. 20% 70-79 34%, 80% and + 33.

No single cause has been identified but research has led to important acquisitions. Genetics of familial polyposis adenomatous (FAP) and knowledge of oncogenes and tumor suppression genes led to understand that the p53 locus on chromosome 17 is abnormal in 70% of cases. In most tumors are at least two chromosomal alterations. Other conditions associated with risk of colorectal cancer are: Peutz-Jeghers, juvenile polyposis.

Ambentali factors also play their role, physical activity is important and leads to reduced risk of cancer, nutrition has important role in the prevention of colon-rectal cancer, and contain fibers, as confirmed by a European study (EPIC), where RR = 0.75; (diet). For alcohol, only heavy drinkers increased incidence of cancer is 1.41 to 1, but alcohol consumption is> 30 g / day. Smoking is associated with increased cancer risk of at least 2 times (Giovannucci et al.) Regarding sex and hormones, it would seem that women have a aminore incidence of cancer, on the other hand, does not seem that hormone therapy in postmenopausal women Possoni play a role in this respect. Instead an important role in preventing appropriate therapy is given by NSAIDs, such as aspirin. A study of the American Cancer Society is a 40% reduction in risk, and a Swedish study of 37%, Crohn's disease and UC are at high risk of cancer. Subjects with primary sclerosing cholangitis and a family history of rectal cancer may have a greater risk of developing cancer if they have an inflammatory bowel disease. The same applies to that Acromegaly is associated with cancer risk, RR = 2.04. Infection with human papilloma virus in anal sex are at risk of cancer.

.
... In Western populations with intermediate incidence about 2 / 3 of tumors are localized in the sigmoid colon and rectum, the rest evenly in the rest of the colon. Tumors spread by local invasion, spread to distant crosses the blood vessels and lymphatic and / or directly into the peritoneal cavity. The affected organ par excellence by metastases is the liver. Dukes' classification, proprosta already in 1932, was amended and updated, but the most popular. The classification provides a breakdown at times A, B, C1 and C2. In A, the tumor is confined to the intestinal wall, with B extending through the muscle, but does not involve lymph nodes, affects the lymph nodes proximal to C1, C2 also in the distal.

Symptoms: the classic ones are given by the alteration of the hive, left constipation is prevalent, while rettorragia or other forms of hemorrhage with release of live blood, occur in the more distal, proximal to have a late onset, sometimes even with anemia. Therefore only the search for the faecal occult blood may be a good screening of the population.

Diagnosis. The diagnosis relies on physical examination is usually normal, except for the presence of a 'anemia or a palpable abdominal mass, the digital rectal examination and sigmoidoscopy are the examinations of choice, sometimes preceded by a double contrast barium enema, today less used. In this case it is clear from reading the sheet looks at apple core, or plaque or polypoid lesion or saddle. At diagnosis the tumors are small, with rounded edges and detected, or if large are protruding into the lumen (the blind) and / or may give stenosis pinch.

.. The evidence that in the colon, the flat lesions, namely flat mucosal lesions are much more frequent and dangerous than previously thought because they represent those adenomas and depressed lesions are advanced, the fact that it is now possible to assess " pit pattern, that can distinguish between hyperplastic and adenomatous lesions that can degenerate into malignant, this has enabled the development of cromoendoscopia. Until now the traditional endoscopy could only see the surface lining of the colon, and low resolution, not being able to obtain information on the fine structure or the histological features of mucosal and submucosal layer. The development of 'a magnification endoscope has made the accurate assessment of the mucosal surface. The fact is, however, that this technique is currently more widespread in the East, although spreading rapidly in Western countries. With the recent introduction of these new technologies that use mainly high resolution, the "magnification" (ie the magnification of the new endoscopes with more pixels solving, up to 850,000 against 200,000 of the old endoscopes) and the interaction between some chemicals (or light) and the tissues will be possible soon make biopsies more targeted, increasing the efficiency of diagnostic endoscopy. The term "cromoendoscopia" means the use of a foreign substance on the surface of the gastrointestinal tract to enhance visualization of one or more characteristics of the mucosa. The substances used are chemical dyes that react with the elements present in the mucosa (vital dyes) or they stay in small structures on the mucosal surface (contrast dyes). The vital dye commonly used in the colon is the methylene blue, which is absorbed from the cytosol of tissues like small intestine, the colonic mucosa and epithelia affected by intestinal metaplasia. The vital staining technique is based on the principle that dysplasia and cancer absorb the methylene blue to a lesser extent.

.
.. This is an example indigo carmine dye contrast. The dye is sprayed onto the mucosa with a special catheter. At present, the maximum capacity is reached magnification of 170x. With the color contrast and magnification, the mucosa of the colon appears as a set of numerous pits (pits) which are actually openings of the crypts of Lieberkühn. These can be seen only with an endoscopic instrument magnification. The tiny grooves on the mucosal surface, the smallest observable detail with a standard endoscope, circumscribe areas that contain 40 to 60 pits. Several systems have been proposed for the classification of pit pattern. The best known classification recognizes six types and was developed by Kudo This classification is based on a close correlation between the pit pattern, other endoscopic features and histology of the lesions. The same author, in a study published in 2001, achieved a sensitivity of 93.8% and a specificity of 64.6% in differentiating lesions containing adenocarcinoma or less.

De novo cancer "

This is the development of colorectal cancer without adenoma-carcinoma sequence (lesion type IIc) The depressed colorectal cancers are often referred to Kudo disease 15 years ago. They represent 2.3% of all colorectal cancers, but not in tumors with submucosal invasion of the percentage of depressed type was 33%. If we look at very small lesions, ie below 10 mm, then you can say I'm 66%. For pattner type III L, IV and VI shows the endoscopic polypectomy as a first treatment and the investigation shows that if histological invasion of the submucosa and muscular wall, lymph nodes and vessels, then by an absolute indication for surgery (SM1-a, + ly or v + sm1c, sm3), and if the lesion is limited to the mucosa or just simply extended to the submucosa, with negative lymph nodes and vessels, you can do follow-up (sm1a-b, ly - and v-). The conventional endoscopy allows the identification of polyps and small, in fact, cancer depressed or flat, but now we see more, thanks to cromoendoscopia, so in 59-62% of cases vs 41-43% traditional endoscopy found in it depressed cancer, representing 23 and even 30% of total cases delel cancerous lesions, as shown by a recent Swedish series. The lesions are flat on average 16 mm but are already talking about cancer or invasive lesions with high grade dysplasia, especially in the right colon (56% vs 42% of cases of polypoid lesions)

Other techniques in development.


CTC or the colongrafia TC, that is a reconstruction of virtual colonoscopy survey prepared by the PC after TAC. It displays the polyps <6 mm with a sensitivity of 88, 7%, and specificity of 79.6%.

EUS.

Already established technique that allows visualization of the 5 layers of the wall of the colon, with mucosal and submucosal invasion display (T1), the muscular layer (T2), perirectal T3, T4 and parenchyma. In addition you can view or not lymph nodes (N0 or N1) If the nodes are not obvious, that are isoecoici context with no evidence of their tissue metastasis.

Colon polyps

Colon polyps can be neoplastic, inflammatory or hyperplastic, but lipomas. The hamartomatous polyps are characteristic of juvenile polyposis and Peutz-Jeghers. Inflammatory and hyperplastic polyps than are found in inflammatory bowel disease.

other links on gastroepato

Adenomatous polyps: rettorragie can cause cancer and have potential, especially if tewndono hairy appearance (frayed) or are larger than 2 cm. Must be removed as soon as identified during endoscopy. The tubular adenoma of 15 mm in size and pedunculated, villous adenoma is large and sessile, ie without stem. Adenomas have metaplastic potential until the dysplastic epithelium not through the muscularis mucosae into the submucosa. In this case terms are used for malignant polyp or carcinoma in early stage (!)

metaplastic or hyperplastic polyps are often found, even multiple, although harmless, sometimes hiding the risk of adenomas elsewhere.



Gastric cancer.

The cancers of the stomach in most cases are malignant and represent 15% of all deaths from cancer, it is mostly adenocarcinomas, and lymphomas, liposarcomas represent a minority. Benign tumors are represented by polyps (adenomatous, hyperplastic and hamartomas), leiomyomas and lipomas.



Endoscopic examination can save the life of the patient who complains dyspepsia: in fact in Japan early gastric cancer, which is one aspect of ulcerated tumor initial (differential diagnosis with gastric ulcer!), Is diagnosed in time, we have the diagnosis is unfortunately the later.

other links on gastroepato

The endoscopic picture of gastric cancer-is-said to neoplastic ulcer margins detected, or an ulcer or a benign tumor or nodular vegetans. Less common is the infiltrative type, known as linitis plastica, where the tumor extends to the whole gastric wall.



Then, the gastric cancer is divided into:

polypoid type

type diffuse infiltrative

The ulcerated type

From the perspective of histological (tissue):

gastric cancer may have a glandular pattern and bowel cancer has the appearance of vegetating mass in the lumen and expansive, this being the most common form.



Preneoplastic

Gastric polyps can be considered as precancerous lesions at high risk! The other precancerous conditions are pernicious anemia, adenomatous polyps and intestinal metaplasia and gastric previous surgery. It 'been called into question even the chronic gastritis associated with H. pylori. The importance of Barrett's esophagus in the pathogenesis of gastroesophageal junction dell'adenocarcinoma is indisputable.

Gastric polyps are classified in types:

hamartomatous

Regenerative

hyperplastic

adenomas (they have malignant potential, with high risk when they are multiples or when the diameter exceeds 2 cm).

Other cancers:

The leiomyomas are the most common benign tumors of the stomach and autopsy studies show that are the most common tumors of the gastrointestinal tract. Originate from smooth muscle of the stomach are large, pedunculated, polypoid in appearance, ulcers and bleeding, the problem is whether there is any possible potential malignancy, which is sometimes confirmed by the presence of metastases.

Gastric lymphomas that can be isolated or part of a disseminated process, has been associated with AIDS and biopsy is essential for diagnosis.

Other gastric cancers, in metastatic lesions to pancreatic adenocarcinoma, ovarian or breast cancer. Kaposi's sarcoma can occur not infrequently in patients with AIDS in the stomach. In this case the appearance is pseudopolipoide, sessile, pointed, deep red, which stands on the mucosa of salmon pink.


.......

e- mail E-MAIL here

>>>see first page

>>>see also RICERCA